Affiliation:
1. GRECO, Institute of Aquatic Ecology University of Girona Girona Spain
2. Plant Physiology Unit, Department of Environmental Sciences University of Girona Girona Spain
3. Molecular Microbial Ecology Group (gEMM‐IEA), Institute of Aquatic Ecology University of Girona Girona Spain
4. Department of Ecology and Hydrology University of Murcia Murcia Spain
5. Department of Evolutionary Biology, Ecology and Environmental Sciences University of Barcelona Barcelona Spain
Abstract
AbstractInland saline ecosystems suffer multiple stresses (e.g., high radiation, salinity, water scarcity) that may compromise essential ecosystem functions such as organic matter decomposition. Here, we investigated the effects of drought on microbial colonization and decomposition of Sarcocornia fruticosa woody stems across different habitats in a saline watershed: on the dry floodplain, submerged in the stream channel and at the shoreline (first submerged, then emerged). Unexpectedly, weight loss was not enhanced in the submerged stems, while decomposition process differed between habitats. On the floodplain, it was dominated by fungi and high cellulolytic activity; in submerged conditions, a diverse community of bacteria and high ligninolytic activity dominated; and, on the shoreline, enzyme activities were like submerged conditions, but with a fungal community similar to the dry conditions. Results indicate distinct degradation paths being driven by different stress factors: strong water scarcity and photodegradation in dry conditions, and high salinity and reduced oxygen in wet conditions. This suggests that fungi are more resistant to drought, and bacteria to salinity. Overall, in saline watersheds, variations in multiple stress factors exert distinct environmental filters on bacteria and fungi and their role in the decomposition of plant material, affecting carbon cycling and microbial interactions.
Funder
Ministerio de Ciencia e Innovación
Agencia Estatal de Investigación
Agència de Gestió d'Ajuts Universitaris i de Recerca